题解 | #统计每个学校的答过题的用户的平均答题数#
统计每个学校的答过题的用户的平均答题数
https://www.nowcoder.com/practice/88aa923a9a674253b861a8fa56bac8e5
select u.university,avg(question_cnt) as avg_answer_cnt from user_profile u inner join (select device_id,count(question_id) as question_cnt from question_practice_detail group by device_id) q on u.device_id=q.device_id group by u.university order by university asc;
海康威视公司氛围 515人发布